养猪废水培养微生物絮凝剂产生菌群B-737及发酵特性

用养猪废水作为产絮菌群B-737的廉价替代培养基,研究了养猪废水COD浓度、外加草酸铵、磷酸盐的量对B-737菌群生长和产絮效果的影响,并在最优培养基下进行发酵动力学模型拟合.结果表明,该养猪废水本身具有较合适的碳氮比(COD约为3 000 mg.L-1,TN约为170 mg.L-1),无需外加碳、氮源,只添加1.6 g.L-1K2HPO4,0.8 g.L-1KH2PO4时,菌群B-737在其中发酵18～24 h便能达到1.5 g.L-1产絮量,同时对废水本身COD、TN削减率分别为61.9%和53.6%.不仅将微生物絮凝剂的培养基成本降低90%左右,也为养猪废水提供了一条新的资源化途径.用Logistic和Luedeking-Piert方程分别研究产絮菌群B-737分批发酵的生长和产絮动力学,获得了相应的动力学模式.     

Urbanization and environmental policy effects on the future availability of grazing resources on the Mongolian Plateau: Modeling socio-environmental system dynamics

The rangelands of the Mongolian Plateau are dynamic socio-environmental systems that are influenced by a complex network of drivers, including climate, social institutions, market forces, and national-scale policies affecting land access and management. The sustainability and resilience of rangelands in this region depend on the ability of residents and policy makers to quickly respond by adapting livelihoods and land uses to changes in environmental and socio-economic conditions, but the responses of the system to these changes are often non-linear and difficult to predict. We developed a system dynamics model to understand how the human, natural, and land-use processes in the Mongolian rangeland ecosystem interact to produce dynamic outcomes in both grassland productivity and livestock populations. We developed two separate models based on a common integrative framework for two case study areas: Suhkbaatar Aimag in Mongolia and Xilingol League in Inner Mongolia. We used future scenarios for each region generated with stakeholder input to forecast trends in grassland area, livestock numbers, and biomass under alternative climate, socioeconomic, and land-use futures. By incorporating stakeholder-developed scenarios, we were able to explore future scenarios tailored to the particular questions and concerns relevant to the individual study areas. We find that while there are many similarities in the factors driving system dynamics in the two countries, the trajectories of key grassland resources are quite different, both between the two study regions and across the individual scenarios. Environmental policies play a key role in Xilingol, while economic development is a key driver in Sukhbaatar. Urbanization dynamics will be a major influence on the availability of grassland resources in the future.     

杉木人工林生态系统的生物地球化学循环Ⅰ:养分归还动态

在福建南平地区 ,对林龄和密度不同的两片杉木人工林的凋落物和森林降水化学进行了 3a(1994～1996 )的定位研究 .株密度n =2 370hm-2 的 16a生林分 (标记为FFC)和株密度n =1180hm-2 的 41a生林分 (标记为XQF)的年凋落量分别为 6 2 10 .7kghm-2 和 3 146 .2kghm-2 ,其中落叶分别占总重量的 76 %和 6 8% .凋落物中 5种主要营养元素的年归还量分别为 173.92kghm-2 和 84.2 0kghm-2 ,其数量大小顺序均为Ca >N >Mg >K>P ,并在 4月份和 11月份出现两次峰值 .在两监测样地 ,降水通过林冠后养分富集现象均十分明显 .降雨、穿透雨和树干径流中养分浓度呈现显著的季节变化 ,均以夏季最低 ,冬季最高 ,春秋季居中 ,这种格局强烈受降雨量的控制 .在两林分中降水引起的 5种元素的年淋溶量分别为 173 .33kghm-2 和 10 7.5 3kghm-2 ,大小顺序为K >Ca >Mg ,而N(及FFC的P)出现负值 ,表明其被林冠层直接吸收 .林龄和密度对生态系统的养分归还具有重要影响 .图 5表 4参 15     

室内空气品质评价

介绍国内外有关室内空气品质的评价方法，着重介绍CFD和多区域两类模拟方法。     

Seasonal Dynamics of Cattle Reproduction in the North

Russian Journal of Ecology -     

均相阳离子隔离阴阳极室电化学降解含酚废水实验及其动力学研究

在隔离阴阳极室的条件下进行电化学法降解含酚废水实验 ,结果表明 ,在 2 5～ 4 5℃的低温范围内 ,苯酚的转化率能达到 95 %以上。反应动力学研究揭示 ,其活化能Ea =12 75～ 16 0 6kJ mol,与一般化学反应的活化能Ea =6 0～2 5 0kJ mol相比 ,本实验的活化能很低 ,即反应所要克服的势能垒很低 ,反应更易进行 ,这是电化学脱酚速率快 ,降解彻底的重要原因 ;另外 ,不同电解液对比实验显示 ,降解苯酚时在碱性电解液中更为有效     

洞庭平原褐家鼠种群动态和繁殖特性

褐家鼠是洞庭平原稻作区的主要害鼠之一，在房舍区数量动态复杂，季节消长基本上属春冬双峰型，在农田区数量季节消长为夏秋双峰型。褐家鼠总雌性比为５２．０％，全年繁殖．３～１０月为繁殖盛期，盛期平均怀孕率为３４．９１±８．６９％，平均胎仔数为８．２±ｌ．０，４、７、９月出现怀孕高峰，１１月至翌年２月为繁殖低潮期。褐家鼠在洞庭平原７０年代数量较低，８０年代初暴发成灾，８０年代后期数量有逐步下降趋势。针对种群特征，提出了控制褐家鼠种群数量的对策。     

The Effect of Soil Cultivation on the Humus State of Gray Forest Soil in the Middle Urals

The results of studies on the humus state of soils in agrosystems of the Middle Urals (1984–1997) are described. It is shown that the change of agricultural technologies (crop rotation, doses of organic fertilizers, etc.) transforms environmental conditions and the direction of humus formation processes. Parameters such as the concentrations of humus and water-soluble carbon and soil potential for humus accumulation reliably characterize the humus state of arable soil and allow the mobility and migration rate of humic substances to be monitored.     

武汉市夏季大气挥发性有机物实时组成及来源

利用在线监测仪器获取了武汉市2019年6～7月环境大气中102种挥发性有机物（VOCs）小时浓度数据.观测期间ρ（VOCs）范围为24.9～254μg·m^-3,平均值为（67.7±32.2）μg·m^-3.依据臭氧浓度标准,将观测期间划分为清洁日和污染日,对比分析清洁日和污染日气象条件、 VOCs浓度、组成、臭氧生成潜势和来源差异.污染日NO_x、 CO和VOCs的平均值分别超出清洁日34.9%、 25.0%和27.8%.污染日烷烃、烯烃、芳香烃和含氧VOCs分别比清洁日高40.7%、 39.5%、 26.9%和21.5%.污染日总臭氧生成潜势为（102±69.6）μg·m^-3,超出清洁天33.5%.污染日液化石油气燃烧、工业排放、机动车排放、天然源和溶剂使用的平均贡献率分别比清洁日低3.4%、 2.5%、 0.2%、 1.3%和1.4%,油气挥发源平均贡献率比清洁日高8.8%.机动车排放源和油气挥发源的日变化均呈现早晚高、午后低的特征,与早晚高峰排放有关;LPG燃烧的日变化与餐饮油烟排放变化一致.浓度...